Apparatus for forming metal parts



Dec. 24, 1940. E. J.'GRE|F 2,225,988

APPARATUS FOR FORMING METAL PARTS Filed April 9, 1937 3 Sheets-Sheet lE. J. GREIF 2,225,988

APPARATUS FOR FORMING METAL PARTS Dec. 24, 1940.,

3 Sheets-Sheet 2 Filed April 9, 1937 fizz/6,1237

Greg

Dec. 24, 1940. E. J. AGREI'F 2,225,988

APPARATUS FOR FORMING METAL PARTS Filed April 9', 1937 3 Sheets-Sheet C5Z29 J0 Jm 16 .205 I 95 I III jzz/ezzlrs [2 (2rd J we? Patented Dec. 24,1940 UNITED STATES PATENT OFFICE Edward J. Greif, Chicago, Ill.,assignor to Borg- Warner Corporation, Chicago, Ill... acorporation ofIllinois Application April 9, 1937, Seri'al'No. 135,990

10 Claims.

from the following detailed description of the invention when takentogether with the accompanying drawings, which form a part thereof andin which:

Figs. 1 to 5 show the Various stages in the formation of a receptacle inaccordance with this invention.

20 Fig. 6 is an elevation in section through a portion of the apparatusused to give the receptacle the form shown in Fig. 3.

Fig. 7 is a fragmentary plan view of the apparatus used to give thereceptacle the form shown 25 in Fig. 4.

Fig. 8 is an elevation in section through a portion of the apparatus ofFig. '7, showing the apparatus in its initial position.

Fig. 9 is an elevation in section through a portion of the apparatus ofFig. 7, showing the apparatus in its final position and showing theactuating means for the apparatus.

Fig. 10 is an elevation in section through a portion of the apparatusused to give the receptacle the form shown in Fig. 5, the apparatusbeing shown in its initial position.

Fig. 11 is an elevation similar to Fig. 10, but showing the apparatus inits final position; and

Fig. 12 is a fragmentary side elevation of the apparatus of Fig. 10,showing the means for placing the apparatus of Fig. 10 in its finalposition.

The same reference characters are used to designate similar partsthroughout the various figures of the drawings.

In its preferred form, this invention comprises broadly means forclamping a receptacle at or near the point at which it is being shaped,and means operable from within the receptacle to give it the desiredform. The receptacle shown in Fig. 3 is formed by clamping it in a presswith a collet ring and forcing the inner end downward. The receptacleshown in Fig. 4 is formed by inverting the receptacle, placing a 55three-part upper die in the channel formed between the side and inturnededge, and forcing the upper die against a lower supporting die. Novelmeans are provided for forcing the upper die downward and for strippingthe receptacle from the lower die. The form shown inFig. 5 is obtainedby supporting the receptacle in an inverted position on a track under arevolving roll and raising the track to cause the roll to curl theexposed end of the receptacle radially outward.

The novel method used in the formation of the receptacle includes thesteps used to obtain the forms shown in Figs. 2 to 5 and consists inrolling the open end of the receptacle inward to form the bottle-neck ofFig. 2, then bending the neck downward into the receptacle to form aconical surface, then changing the conical surface to form the seat andcylindrical skirt shown in Fig. 4, and, lastly, curling the skirtoutward to remove the sharp edges from the inner surface of the opening.

By the method and apparatus of this invention, a receptacle can be madeto have a sunken cover seat and a smooth inner edge without the expenseand waste of forming the seat portion from a separate sheet as isusually done by other methods. The result is a one-piece receptaclewhich is neat in appearance and economical to make.

For purposes of illustration, this invention will be described withreference to the formation of a washing machine tub, but it isunderstood that the invention can be used to'form other receptacles madeof sheet metal.

Referring now to Fig. 1 of the drawings for a detailed description ofthe invention, I5 is a tub which has been formed in the usual manherfrom a single sheet of metal. The tub is provided with a centralaperture l8 at the bottom, asecond aperture I1, which is used fordraining purposes, and a bottle-neck IS. The method and apparatus usedto'form bottle-neck l8 are described in my co-pending application SerialNo. 91,269, filed July 18, 1936 and entitled Machine for formingbottle-necks upon sheet metal tubs (Patent No. 2,170,946, granted Aug.29, 1939). The apparatus may be briefly described as comprising a seriesof rolls which force the end of tub l5 inward in combination withforming blocks, and results in a shape such as that shown in Fig. 1. Forthe formation of the seat shown in Fig. 5, the material above line A-Aof Fig. 1 is superfluous and the tub, therefore, is trimmed along lineA-A to give it the iorm shown in Fig. 2.

Referring now to Fig. 2, it will be observed that tub I5 is providedwith a rounded shoulder I9, a flat portion 20, and an upturned edge orneck 2I. Due to the fact that edge 2I is formed by decreasing thediameter of the tub, the thickness of the material at that part isaccordingly increased. Even though this portion is subsequently to beforced downward and outward and will therefore undergo an increase inits diameter, it will not be forced outward sufficiently to reduce itsthickness to the normal thickness of the tub. The thickness of the metalat edge 2I is therefore reduced, preferably by the rolls which form theneck, to approximately that of the remainder of the tub.

After edge 2| of the tub of Fig. 2 has been reduced in thickness, it isthen bent downward in the form shown in Fig. 3. The apparatus forproducing this form is shown in Fig. 6, and reference thereto is nowmade.

The forming apparatus is comprised of a base casting 22 which iscylindrical in form and'provided with a flange 23 by which it may besecured to a suitable press (not shown). Base casting 22 is provided atits upper end with two or more ears 24, only one of which is shown forsimplicity, and has a counterbore 25 connected by inclined surfaces 26and 2! to the inner and upper surfaces 28 and 29, respectively. Innersurface 28 is slightly larger in diameter than the diameter of tub I5.Located in counterbore 25 is a collet ring 38, which is split andnotched from opposite sides as at 3| and 32 to render it contractile. Itis provided with inclined surfaces 33 and 34 which correspond toinclined surfaces 26 and 21 respectively in base casting 22. It isapparent that pressure upon upper surface 35 of collet ring 30 willcause surfaces 33 and 34 thereof to slide inward and downward uponsurfaces 26 and 21, thereby reducing the diameter of collet ring 30. Thering normally is of a diameter comparable to the diameter of surface 28of base casting 22.

The press is preferably provided with two rams (not shown) to the outerone of which a holder 36 is secured. Holder 36 is likewise provided withtwo or more cars 31 and 38 corresponding to ears 24 of base casting 22.All of the ears are accurately drilled and reamed to receive locatingpins (not shown) which are removed after the base casting and holder aresecured to their respective portions of the press.

The inner ram of the press is secured to a die member 39 which is guidedin holder 36 by surfaces 46 and 4| in the holder. The downward motion ofdie member 39 is limited by shoulder 42 on holder 36, which abuts aflange 43 on die member 39 when said die member is at the bottom of itsstroke. The bottom portion of holder 36 is shaped as shown at 44 toreceive the upper end of tub I5. A portion of the surface of die member39 is recessed in such a manner as to provide a shoulder 45 whichpermits inner ends 2! of tub I5 to remain at a slightly smaller diameterthan the portion at shoulder 45. A pressure pad 46, which is urgedupward by a plurality of compression springs 41 and guided in its upwardmotion by pins 48, is used to force tub I5 against holder 36.

The operation of the apparatus of Fig. 6 is as follows:

With the press in its starting position, holder 36 and die member 39 areraised above ring 30 and base casting 22. There is no pressure on ring38 and hence it is in its expanded position. A tub of the form shown inFig. 2 is inserted into base casting 22 until it rests upon pressure pad46. The press is then operated, whereupon holder member 36 descendsuntil it contacts shoulder I9 of the tub and thereafter forces tub I5downward against pressure pad 46 until its lower surface bears againstthe upper surface 35 of collet ring 30. For the remainder of its stroke,holder 36 will force ring 30 downward and inward, thereby securelyclamping tub I5 in base casting 22. With tub I5 securely clamped, theinner ram forces die member 39 downward to give tub I5 the form shown inFig. 3. Pressure from die member 39 is not transmitted to pressure pad46 due to the clamping action of collet ring 30, The inner ram thenraises die member 39, stripping it from the tub, which is still held byholder 36, and then said holder 36 is raised, thereby relieving colletring 30 of downward pressure. Collet ring 30 therefore springs outwardto release tub I5, and the tub may then be removed for further formingoperations.

Referring next to Fig. 3, it will be observed that tub I5 now has acylindrical portion 49 and a conical skirt 50. The seat is formed fromskirt 50 which is purposely made conical for reasons hereinafter tobedescribed.

The seat-forming apparatus is shown in Figs. '7, 8 and 9. In thesefigures, 66 is a base casting which is provided with a flange 6|. Basecasting 60 is apertured at 62 to receive a bushing 63 in which ismounted a post 64. Threaded over bushing 63 is a lower die member 65which is made of two parts 66 and 61, respectively. Part 6! is a splitring having a normal inner diameter which is greater than the outsidediameter of portion 66. The outer surface 68 of ring 61 and the innersurface 69 of flange 6| are made conical, so that downward pressure onring 6! causes it to slide along surface 69 and compresses it againstportion 66. Ring 61 preserves the form of the shoulder II! of the tub,and part 66 forms a nose ID. a seat II, and a cylindrical portion I2connecting seat II and nose I0, leaving a cylindrical end I3.Cooperating with lower die 65 is an upper die I4 which is in the form ofa ring. Upper die I4 is split as at III! into three or more parts sothat it may readily be removed from and inserted into, the nose of thetub.

The means for forcing upper die I4 against lower die 65 comprises aplurality of jaws I5 which are pivoted in bearings I6 secured by bolts31, or otherwise, to part 66 of lower die 65. As shown in Fig. 7, jawsI5 are relatively closely spaced. The spacing however, is sufficient topermit a bolt I8 to pass therebetween. Bolts I8 are threaded throughsuitable apertures in a pressure plate I9, which overhangs pivots I6,and thence between adjacent jaws to a nut 86. Said nut is wider than thespace between adjacent jaws and cannot be raised without likewiseraising jaws I5.

Pressure plate I9 is also threaded over bolt 64 and abuts ashoulder 8|thereon. Downward motion of bolt 64 therefore causes pressure plate I9to be lowered with it. Guide posts in the form of bolts 82 are providedfor pressure plate I9, said bolts being threaded through suitableapertures therein. Apertures 83 are enlarged at their lower extremitiesto receive compression springs 84 which surround bolts 82 and pressagainst part 66 of lower die 65. Springs 84, therefore, serve to raisepressure plate I9 after it has been lowered by post 64, the height towhich it is raised being limited by the height of head 85 of bolt 82above lower die 65. The head 86 of bolt 18 is likewise removed frompressure plate I9, but a shorter distance, so that upward movement ofpressure plate I9 first raises the plate from the jaws I5 and then,through contact with heads 86, raises bolts 18, and with these bolts,through nut 80, the jaws I5. Said jaws will swing about pivots I6 andwill assume a position such as that shown in dotted lines in Fig. 9. Itwill be observed that in the raised position jaws I5 do not extend overedge I3 of tub I5 and hence the tub can be lifted over the jaws.

In the form of apparatus shown in Fig. 9, power for lowering plate I9 issupplied through post 64 from its upper end, which is threaded throughaperture it in tub I5. It is understood, however, that for tubs nothaving an aperture such as Iii, the power could likewise be suppliedfrom the lower end of post 84.

The operation of the seat-forming apparatus can best be described withreference to Fig. 8.

- A tub having the form shown in Fig. 3 is inverted and upper die I4 isinserted in the nose of the tub. It will readily be seen now that if thefolded portion of the nose were not made conical as at 5E3, downwardpressure of upper die I4 would cause this portion to buckle. The conicalform, however, causes edge I3 torest upon rounded corner 81 of upper dieI4 and allows the edge to slide therearound without buckling whenpressure is applied. The inverted tub with upper die 74 in place is theninserted into ring 61 of lower die 65. At this point ring 61 is in itsexpanded position and hence does not contact tub I5 except at thelowermost point of shoulder I9. Post M is then lowered, carrying with itpressure plate "I9, which lowers jaws I5 upon upper die 14. Continueddownward movement of pressure plate I9 causes upper die M to contact thenose of the tub, thereby pinching the tub between itself and ring El.From this point onward, ring 61 commerces to contract and descend. Atthe completion of the stroke, ring 61 is fully contracted and upper die14 has completed the formation of the seat in tub I5. Upward movement ofpost 64 then raises jaws I5, relieving upper die 14 of pressure,

7 and near the top of the stroke, ring 61 is raised by means of chains(not shown) thereby spreading it and simultaneously stripping tub I5from portion 66 of lower die 65. Upper die I4 is then removed from tubI5 by inserting a suitable tool into groove 88 provided for that purposeand pulling it from nose 'II] of the tub. The tub now has the form shownin Fig. 4 and is ready for the curling operation.

Referring lastly to Figs. 10, l1 and 12, the curling apparatus is seento comprise a circular track 88, which fits into the seat of the tub,and a curling roll 9i provided with a cylindrical portion 92 adapted toengage track 5%. Roll 9I is mounted on a bracket 93 which in turn issecured to an arm at threaded over a shaft 95. Track 90 is supportedfrom a camming ring 96 through rollers 8'! which cooperate in cammingslots 98 in ring 96. Rollers 9'! are mounted on axles 98 which may takethe form of screws threaded into track 95. Ring 96 is mounted in amachined recess I08 in frame NH and is free to rotate relative thereto.Track 96, however, is held against rotation with respect to frame IIlIby pins I02. A control lever I83 is secured to ring 96 and provides themeans for rotating said ring.

Shaft 95 is provided with threads I54 and a nut 295 which preventsvertical movement of arm 94 upon shaft 95 and secures arm 95 forrotation with shaft 95. Only one arm and roll are used in this apparatusand hence tub I5 may readily he slipped between the roll and track.

To form the curled edge by the apparatus just described, the tub, whichnow has the form shown in Fig. 4, is placed on track 99, again in aninverted position. Shaft 95 is rotated, carrying with it arm 94 and roll9|, and control lever I03 is gradually pulled forward until cylindricalportionv 82 of roll 9! contacts track 90. The raising action arises fromthe coaction between roller 91 and camming surfaces 98. As shown in Fig.12, it is obvious that motion of control arm I03 to the right. will.cause rolls 9'! to climb upward on cam surfaces 98 and raise with themthe cooperating axles 98, thereby raising track 90 with respect to frameI When track 90 contacts roll 9!, as shown in Fig. 1]., edge I3 willhave been turned outward by the sloping contour of roll SI After theedge has been curled, lever I 93 is moved in the opposite direction,thereby lowering track 88' and permitting tub I5 to be removed from theapparatus. The tub now has the form shown in Fig. 5.

It is apparent from the foregoing description,

that by my method a receptacle can be made to have a sunken cover seatof reduced diameter without requiring the use of a separate sheet ofmetal for the formation thereof. The seat may likewise be formed in sucha manner that the edge, which is usually sharp, is curled outward wherewill not come in contact with clothing and other materials which may bepulled across the seat. The metal of the seat is not unduly strained andis free from undesirable wrinkles. It is apparent also that by mymethod, dies of a greater diameter than the diameter of the seat may beused internally of the tub and yet will not require a special opening inthe tub for their insertion and withdrawal.

It is understood that the foregoing description is merely illustrativeof a preferred embodiment of the invention and that the scope of theinvention, therefore, is not to be limited thereto, but is to bedetermined by the appended claims.

I claim:

1. In an apparatus for forming a concealed cover seat in a relativelythin walled sheet metal receptacle having a neck flange convergingupwardly and inwardly in an intermediate stage of formation, a male dieelement adapted to engage the inner region of said flange and to fold itaxially into the interior of the receptacle, a contractile colletadapted to receive the receptacle in a position centered below the dieelement, means movable independently of. and in timed relation to themovement of said die element, adapted to-engage said collet and to movethe same axially, and means cooperating with said collet when thus movedaxially so as to cause the collet to contract into frictional engagementwith the side wall of the receptacle and exert a restraining forceagainst further axial movement of the receptacle for supporting the sameagainst buckling under the pressure of said die element.

2. In an apparatus for forming a concealed cover seat in a relativelythin walled sheet metal receptacle, a male die element adapted to engagethe upper edge region of said receptacle and to fold it axially into theinterior thereof, a member adapted to be engaged by the bottom of thereceptacle and to oppose the pressure of said die element, a contractilecollet adaptedv to receive the receptacle in a position centered belowthe die element, means movable independently of and in timed relation tothe movement of said die element, adapted to engage said collet and tomove the same axially, and means cooperating with said collet when thusmoved axially so as to cause the collet to contract into frictional en-5, gagement with the side wall of the receptacle and thereafter torestrain further axial movement of the collet, for absorbing the axialpressure imposed upon the receptacle by said die element in sufiicientquantity to reduce the pressure transmitted through the receptacle tothe said member sufficiently to avoid deformation of the receptacleunder such pressure.

3. In an apparatus for forming a concealed cover seat in a relativelythin walled sheet metal receptacle, a male die element adapted to engagethe upper edge region of said receptacle and to fold it axially into theinterior thereof, a yieldingly mounted bottom member adapted to receivethe lower region of the receptacle and to yieldingly oppose the axialpressure of said male die element, a contractile collet adapted toreceive the intermediate region of the receptacle, means movableindependently of and in timed relation to the movement of said dieelement and adapted to engage said collet in advance of the workingportion of the stroke of said die element and to move the same axially,and means cooperating with said collet when thus moved axially so as tocause the collet to contract into frictional engagement with the sideWall of the receptacle and thereafter to restrain further axial movementof the collet during the working stroke of the die member for absorbingthe axial pressure of said die element in sufficient amount to avoiddeformation of the receptacle between the die element and said bottommember.

4. In an apparatus for forming a concealed cover seat in a relativelythin walled sheet metal receptacle having a neck flange converging up-40 wardly and inwardly in an intermediate stage of formation, a male dieelement adapted to engage the inner region of said flange and to fold itaxially into the interior of the receptacle, a holder movableindependently of and in timed rela- 45 tion to the movement of said maledie element and adapted to receive the upper region of the receptacle, acontractile collet arranged below and in register with said holder andadapted to be engaged by said holder and thereby moved 50. axially, andmeans cooperating with said collet when thus moved axially for causingthe same to contract into frictional engagement with the intermediateregion of the side wall of the receptacle and thereafter to restrainfurther axial 55 movement of the collet While the die element is foldingthe flange into the receptacle for supporting the same against bucklingunder the pressure of said die element.

5. In an apparatus for forming a concealed 60 cover seat in a relativelythin walled sheet metal receptacle, a male die element adapted to engagethe upper edge region of said receptacle and to fold it axially into theinterior thereof, an annular holder arranged to receive the upper re- 65gion of the receptacle and movable independently of and in timedrelation to the movement of said male die element, a contractile colletarranged to receive the intermediate region of the receptacle, andadapted to be engaged by said holder in advance of the working portionof the stroke of the male die element and thereby moved axially, abottom member adapted to receive the lower region of the receptacle andto oppose the pressure of said male die element transmitted with saidcollet when thus moved axially so as to cause the collet to contractinto frictional engagement with the receptacle and thereafter torestrain further axial movement of the collet to cause said collet tocooperate with said bottom member in supporting the receptacle againstdeformation under said pressure.

'6. In an apparatus for forming a concealed cover seat in a relativelythin walled sheet metal receptacle, a male die element adapted to engage10 the upper edge region of the receptacle and to fold it axially intothe interior thereof, a contractile collet adapted to receive thereceptacle in a position centered below the die element, means movableindependently of said die element and 15 adapted to engage said colletin advance of the working portion of each stroke of said die element andto move the same axially, and means cooperating with said collet whenthus moved axially so as to cause the collet to contract into frictional20 engagement with the side wall of the receptacle and to support thereceptacle against deformation under the pressure of said die elementtransmitted through the receptacle.

'7. In an apparatus for forming a concealed 25 cover seat in arelatively thin walled sheet metal receptacle, a male die elementadapted to engage the upper edge region of said receptacle and to foldit axially into the interior thereof, a bottom member adapted toyieldingly engage the 30 bottom of the receptacle in opposition to theaxial pressure of said die element transmitted through the receptacle,an annular holder adapted to receive the upper region of the receptacleand to move the receptacle into engagement with said bottom member, acontractile collet adapted to receive the intermediate region of thereceptacle and to be engaged by said holder in advance of the workingportion of the stroke of said die element and to be thereby movedaxially, and means 00- 40 operating with said collet when thus movedaxially so as to cause the collet to contract into frictional engagementwith the receptacle and thereafter to restrain further axial movement ofthe collet to cause the collet to cooperate with said bottom member insupporting the receptacle against said axial pressure withoutdeformation thereunder.

8. In an apparatus for forming a straight-sided receptacle, a die memberadapted to bear against one end region of the receptacle in a directionparallel to the sides thereof to fold the edge of the receptacle, aholder adapted to bear against an adjacent portion of the said endregion of the receptacle in the same direction as the die member, meansengaging the receptacle adjacent the opposite end region for urging saidreceptacle toward the holder, friction means engaging the straight sidesof the receptacle for maintaining said receptacle in position while saiddie member is folding the edge thereof, and means cooperating with thefriction means to take the reaction of the urging means, wherebypressure transmitted through the receptacle to the urging means isreduced below the point at which said 5 urging means can deform saidreceptacle.

9. In an apparatus for forming a straight-sided receptacle, thecombination as described in claim 8, said friction means comprising adeformable ring cooperating with the urging means and having a camsurface, and said means cooperating with the friction means having a camsurface contacting the cam surface of the ring, said cam surfaces beingso disposed that the diameter of through the receptacle, and meanscooprating the ring is reduced as it is acted upon by the 75 urgingmeans, whereby to clamp said receptacle in place.

10. In an apparatus for forming a receptacle, a die member adapted tofold the edge of the receptacle, a reciprocable holder for thereceptacle, a pressure pad for yieldingly urging said receptacle towardthe holder to position said receptacle therein, a reciprocable splitcollet ring surrounding said receptacle and having cam surfaces, and astationary base member surrounding said collet ring and having camsurfaces cooperatively related to said collet ring cam surfaces, thebase member cam surfaces and ring cam surfaces being so disposed as tocause the ring to alter its diameter as the ring is moved relative tothe base member, said holder bearing against the collet ring to move thering relative to the base member, whereby to decrease the diameter ofthe ring and to clamp the receptacle thereto while said receptacle isacted upon by! the die member.

EDWARD J. GREIF.

